Abstract
A method for synthesizing carbon spheres with a tunable particle size and internal structure from polyfurfuryl alcohol (PFA) was developed. By tuning the concentration of a structure directing agent (polypropylene glycol, PPG), we found a mechanism to tune the inner architecture of carbon spheres driven by water-solubility. A mixture of PFA and PPG transferred from the "water-in-oil" phase to an "oil-in-water" phase with an increasing content of PPG because of a difference in water-solubility between furfuryl alcohol (FA), PFA, and PPG. As a result, the internal morphology of the carbon sphere evolved from a "cheese-like" to a "pomegranate-like" structure, which was accompanied by an increasing specific surface area and pore volume. Furthermore, the separation of C(2)H(2) and C(2)H(3)Cl was tested on the 25%-FACS (furfuryl alcohol-based carbon sphere) sample under different activation treatments with CO(2) or CO(2)-NH(3), with the coexisting "cheese-like" and "pomegranate-like" inner structures, owing to its moderate pore volume and mechanical strength. The maximum adsorption capacity of C(2)H(3)Cl reached 0.77 mmol g(-1), while C(2)H(2) was adsorbed in significantly lower quantities. It is believed that the high polarizability and high dipole moment of the C(2)H(3)Cl molecule primarily contribute to the excellent performance of C(2)H(2) and C(2)H(3)Cl separation, and the introduction of polar N-containing groups on the carbon skeleton further promotes C(2)H(3)Cl adsorption.